Delta rotor through feed mixer

Claim 1

A through feed mixer comprising: at least two rotors mounted for rotation in opposite directions about generally parallel axes in a mixing chamber, each of said rotors comprising an elongated polyhedron extending axially in said mixing chamber, each of said elongated polyhedrons having apexes extending generally axially and being generally parallel with one another, a feeding device adapted to supply material to be mixed to an inlet and portion of said mixing chamber under a substantially constant pressure, each of said rotors having a cross-section at right angles to its axis of rotation which is derived from a regular n-sided polygon having similar peripheral portions, each peripheral portion including: a first, narrow section substantially circular about the axis of rotation of said rotor comprising the radially outermost portion of each of said apexes; a second leading section which leads into the first section to provide an acute angle between the second section and a circle defining the outer periphery of said rotor at that cross-section; a third section which is in part, at least, of one of the sides of the polygon; and a fourth relief section extending from the third section towards the first section of the next peripheral portion.